Emmanuel lemaire



E. LEMAIRE.

SAFETY CARTRIDGE FOR MINING PURPOSES.

APPLICATION FILED DEC. 26.1916.

Patented July 22, 1919.

M flwybb/v ATTORNEY itself.

EMMANUEL LEMAIRE, 0F MONS,

BELGIUM.

SAFETY-CARTRIDGE FOR MINING PURPOSES.

Specification of Letters Patent.

Patented July 22, 1919.

Application filed December 26, 1916. Serial No, 139,066.

T 0 all whom it may concern: 1

Be it known that I, EMMANUEL LEMAIRE, citizen of Belgium, residing at Mons, Belgium, have invented new and useful Improvements in Safety-Cartridges for Mining Purposes, of which the following is a specification This invention relates to blasting cartridges used in mines and to the use, in combination therewith, of an incombustible pulverulent material intended to extinguish the flame produced by the explosion of the cartridge in order to prevent the ignition of fire-damp or coal dust and dotroy the harmful and deleterious gases and smoke resulting from the explosion.

It has already been proposed for that purpose, to introduce, ordinary blasting cartridges into the shot-hole, covered with fire extinguishing substances and place the whole, in the first place, in a copper tube or sleeve which was subsequently withdrawn so as to leave in the shot-hole the blasting cartridge or cartridges and the fire extinguishing substance and finally place in front of the charge, a certain quantity of the said substance.

This method which necessitated the employment of skilful workmen and required tedious and complicated manipulations, excluded, in practice, the use of several cartridges at the same time owing to the difficulty of introducing a long sheath in a shothole the axis of which is never rectilinear, so to speak, and also owin to the fact that the flame or fire extinguishing substances could possibly interpose themselves between the diflerent blasting cartridges and thereby have a deleterious effect on the prop-' agation of the explosive wave and give rise to misfires.

It has also been proposed to introduce the blasting cartridges, in the first place, into the. shothole and then-to cover them with extinguishing substances in the shot-hole This method has the same disadvan ages as the preceding one and, moreover, it is quite impossible to make use thereof in upward shot-holes. It is again a complicated operation giving rise to m'isfires.

The proposal has also been made to place the extinguishing substances in the cartridge itself, sequentially with the explosive material, but in that case the extinguishing substances are simply expelled bodily from the shot-hole by the effect of the explosion and are thereby rendered useless. Moreover, this arrangement does not permit of the simultaneous use of two or more cartridges in series.

Furthermore the flame or fire extinguishing substances hitherto in use consisted of salts rich in'water of crystallization or salts capable of decomposition by heat. The first ones rapidly lose their water of crystallization by efliorescene during storage thereby diminishing their flame or fire extinguishing properties; moreover, the water volatilized at the moment of the explosion may, in certain cases, react chemically on the explosion. gases and thus increase the danger of ignition of fire-damp or of coal dust. The same applies to the gases produced by the various salts capable of decomposition by heat.

The safety cartridges in accordance with the present invention, are devoid of the above-mentioned defects as much from the point of view of the flame or fire extinguishing ability as from the manner of employing the same.

To this end, the safety cartridges are formed by a tubular layer of extinguishing material surrounding a single blasting cartridge so that both ends of the latter are not covered by the said tubular layer which has the same or a slightly lesser length as the cartridge.

As the ends of the blasting cartridge are not covered by the extinguishing substances, it is possible to introduce two or more cartridges one after another into the same shothole, just as if they were ordinary blasting cartridges, and one single detonator is sufficient to cause the explosion of all of them without there being any priming difficulty. Moreover, there is no danger of the extinguishing material placing itself between the cartridges, thereby completely avoiding misfires.

The results obtained from the point of view of safety in regard to fire-damp and coal dust, of facility and simplicity of use and of the elimination of misfires, are superior to those which can be produced by other methods.

The accompanying drawing illustrates, by way of example, a plurality of safety cartridges manufactured in accordance with the present invention.

Figures 1 and 2 illustrate one of the cartridges in longitudinal section and in cross section.

Fig. 3 is a longitudinal section through a cartridge the ends of which are differently constructed, and

' Fig. 4, is a separate view of an element of these ends.

Figs. 5 and 6 illustrate in longitudinal section and in cross-section a cartridge with a metallic cover.

Fig. 5 shows a modified construction of the cartridge. 7

Figs. 7 and 8 and Figs. 9 and 10 are longitudinal sections and cross-sections through tubular covers made of extinguishing substances intended to surround the blasting cartridges.

Referring to the drawing, 1 is the blasting cartridge and 2 the flame or fire ex' tingulshing substance the caslng 3 of which made of paper orequivalent material, is folded over at both ends so as to formthe ends 4: to which the explosive cartridge 1 is secured with its ends by means of glue or adhesive substance, in order to prevent the penetration of the extinguishing substance in between these ends 4 and the ends of the blasting cartridge.

In Fig. 3 washers 5 made of cardboard, metal or other suitable material, are stuck onto the folded-over ends of the casin 3 and on these washers 5 are stuck the foldedover edges 14 of sleeves (3 made of paper stuck around the ends of the blasting cartridge 1.

The sleeves 6 may also be made of light cardboard, metal or other suitable material and formed with a collar 11 as shown in Fig. 4. This collar 14 may then be stuck directly onto the folded-over ends of the casing 3 without the interposition of washers 5.

The two sleeves (i may be connected to form one sleeve surrounding the cartridge 1 throughout its length.

A similar cartridge can easily be constructed in such a manner that the explosive cartridge cannot be withdrawn from the safety cartridge without necessarily putting the explosive cartridge into such a condition that it cannot be used.

It is a very great advantage from the point of View of safety, for it is the best protection against i-mprudence on the part of the miners. To this end the latter may be covered with a metallic casing 7, shown in Figs. 5 and 6, made, for instance, of tin,

provided with an end 8 formed with a central opening 9 sufiicient for the passage of a detonator and to permit of the transmission of the explosive wave from one cartridge to another but too small to permit of withdrawing the blasting cartridge.

Another example of an arrangement preventing the explosive cartridge from being used without the safety cartridge consists of closlng both ends of the latter by an annular ring stamped out of cardboard, metal or other suitable material, shown at 7 in Fig. 5". On these rings are stuck the inblasting cartridge and has the same length as the latter; it may be introduced into a shot-hole as readily as an ordinary cartridge without any special operation; it has the same external appearance as an ordinary cartridge and may be supplied quite ready from the factories.

Should it be desired to introduce the blasting cartridge into the extinguishing substance only at the moment of charging the shot-hole, the extinguishing substances may be inclosed, as shown in Figs. 7 and 8, in a tubular casing 10 closed at both ends and having the same length as a single blasting cartridge or a slightly lesser length. The ends of this tubular casing may be closed by sticking thereon cardboard washers 11. In order to render the tubular casing rigid and avoid its being bent under the weight of the extinguishing substance, it may be stink onto a hollow tin cylinder 12 perforated with large holes.

. As shown in Figs. 9 and 10, the extinguishing material or substances, may be slightly agglomerated by any suitable binding agent and molded tubular. In this case the said tube of extinguishing substance, does not require a casing.

For a blasting cartridge of 30 mm. diameter and 12 cm. long, the safety casing may be given a length of 12 cm. and an external diameter of 35 to 40 mm.

For filling up the safety cartridges use is made, in accordance with the present invention, as incombustible pulverulent extinguishing material or substances (a) A mixture of calcium fluorid and sodium chlorid, for instance, in the following proportions Calcium fluorid 50 per cent. Sodium chlorid 50 per cent.

rately. Instead of calcium fiuorid, another calcium salt such as the carbonate or sulfate thereof may be mixed with the sodium chlorid which itself can be replaced by potassium chlorid or ammonia chlorid.

(b) The simple chlorids or the double chlorids of metals or of ammonia, the simple fluorids and the double fluorids of metals or of ammonia, the fluosilicates of metals or of ammonia, anhydrous sodium carbonate or anhydrous potassium carbonate, potassium or sodium nitrate either alone or in mixture with one another or with the substances mentioned under (a). v

These bodies or mixtures of bodies have the following advantages over the other incombustible pulverulent materials which may be used for the same purpose (1) They assure a greater safety.

(2) They diminish to a lesser extent the force of the explosives, notably in comparison with the salts which contain water'of crystallization.

(3) They preserve indefinitely their fire extinguishing properties whereas the salts which contain water of crystallization rapidly lose these properties by efllorescence.

What I claim as my invention and desire to secure by Letters Patent, is

. 1. A safety cartridge ready for use comprising in combination a blasting cartridge, a tubular layer of extinguishing material surrounding said blasting cartridge and leaving the ends of the latter uncovered and a permanent casing containing said extinguishing material.

2. A safety cartridge ready for use comprising in combination a blasting cartridge, a tubular layer of extinguishing materlal surrounding said blasting cartridge and leaving the ends of the latter uncovered and a paper casing containing said extinguishing material.

3. A safety cartridge ready for-use comprising in combination a blasting cartridge, a tubular layer of extinguishing material surrounding said blasting cartridge and leaving the ends of the latter uncovered, a permanent casing containing said extinguishing material and metallic casing having ends formed with a central opening coverlng the safety cartridge.

4:. A safety cartridge ready for use comprising in combination a blasting cartridge,- a tubular layer of extinguishing material surrounding said blasting cartridge and leaving the ends thereof uncovered, a permanent casing containing said extinguishing material, annular rings of hard material fixed to the ends of said permanent casing andwashers of hard material fixed upon said rings.

5. A safety cartridge ready for use, comprising in combination a blasting cartridge, a tubular layer of extinguishing material surrounding said blasting cartridge and prising in combination a blasting cartridge,

a tubular layer of extinguishing material composed of volatile salts surrounding said blasting cartridge and leaving the ends thereof uncovered and a permanent casing containing said extinguishing material.

8. A safety cartridge ready for use, comprising-in combination a blasting cartridge, 7

a tubular layer of extinguishing material composed of halogen salts surrounding said blasting cartridge and leaving the ends thereof uncovered and a permanent casing containing said extinguishing material.

9. A safety cartridge ready for use, comprising in combination a blasting cartridge, a tubular layer of extinguishing material composed of a mixture of calcium fluorid and sodium chlorid surrounding said blasting cartridge and leaving the ends of the latter uncovered and a permanent casing containing said extinguishing material.

10. A safety cartridge for mines comprising an explosive substance in juxta-p'osltion with a flame extinguishing substance composed of a mineral salt which is volatile,

fusi'ble or decomposable at a high temperature, said flame extinguishing material extending and being effective throughout the entire length of the explosive material and being so arranged relatively to the explosive material that the ends of the cartridge are not covered thereby, and moreover being sufliciently powerful to quench the flames of the explosion without the use of a plug or tamping, substantially as described.

11. A safet cartridge for mines compris ing an exploslve substance in juxta-position with a flame extinguishing substance composed of a plurality of mineral salts which are volatile, fusible or decomposable at a high temperature, said flame extinguishing material extending and being efi'ective throughout the entire length of the explosive material and being so arranged relatively to the explosive material that the ends of the-cartridge are not covered therea by and moreover being sufliciently powerful to quench: the flames of the explosion withoutthe use of a plug ortamping, substantially as described. y

12. A safety cartridge for mines, comprisingan explosive substance in molded tubular form and a flame extinguishing material also in molded tubular form arranged concentrically with the explosive substance and extending the entire length thereof without covering the ends thereof, said flame extinguishing material comprising a mineral salt which is volatile, fusible or decomposable at a high temperature and capable of quenching the flames of the explosion without the use of a plug or tamping, substantially as described.

13. A safety cartridge for mines comprising an explosive substance in molded tubular form and a flame extinguishing material also in molded tubular form arranged concentrically with the explosive substance and surrounding and extending the entire length thereof without covering the ends thereof, said'flame extinguishing material comprising a mineral salt which is volatile, fusible or decomposable at a high temperature and capable of quenching the flames of the explosion without the use of a plug or tamping, substantially as described.

14. A safety cartridge for mines consisting of an explosive substance in juxta-position with a flame extinguishing substance comprising a mixture or fluorid of calcium and chlorid or sodium, said flame extinguishing material extending in contact with and being effective throughout the entire length of the explosive material, and being so arranged that the ends of the cartridge are not covered thereby, substantially as described.

15. A safety cartridge for mines comprising an explosive substance in molded tu'bular form and a flame extinguishing material, comprising a mixture of fluorid of calcium and chlorid of sodium also in molded tubular form arranged concentrically with the explosive substance and extending the entire length thereof without covering the end thereof said flame extinguishing mate rial comprising a mineral salt which is volatile, fusible or decomposable at a high temperature and capable of quenching the flames of the explosion without the use of a plug or tamping substantially as described.

In testimony whereof I have signed my name to thisspecification in the presence of two subscribing witnesses,

EMMANUEL LEMAIRE.

Witnesses:

ADOLPHE VoGEL, CHARLES Roy NAsMrrH. 

